There are several potential causes of swollen legs and ankles. Some causes, such as standing or walking for long periods, are normal and generally harmless. However, sudden or chronic swelling in the legs and ankles may indicate an underlying health condition.
This article outlines some potential causes of swollen legs and ankles, and some of the treatment options available.
Below are eight potential causes of swollen legs and ankles.
1. Injury to the foot or ankle
An injury to the foot or ankle could cause swelling in the ankle and lower leg. One of the most common causes of injuries to this area is a sprained ankle.
A sprained ankle can occur as a result of a simple misstep, or a sports or exercise injury. It happens when the ligaments that connect the ankle to the foot and leg are pulled out of alignment.
A person who has a sprained ankle may experience pain and limited mobility in the ankle or foot.
The most common treatment for foot or ankle injuries is the RICE procedure. RICE is an acronym which stands for:
- Rest: Resting the affected foot helps to prevent further damage.
- Ice: Applying ice to the injury helps to numb pain and reduce swelling. People should wrap ice in a towel before applying it to the skin. Ideally, people should apply the ice pack for 10-20 minutes, three or more times per day.
- Compression: Wearing a compression bandage will help to reduce swelling.
- Elevation: Elevating the foot or ankle above heart level will help reduce swelling.
An infection in the feet, ankles, and lower legs can cause swelling in this area.
People who have diabetes are at increased risk of developing an infection in their feet. They should, therefore, inspect their feet regularly for bruising, cuts, and scrapes.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), people who have diabetes and an untreated infection in the foot or legs can develop gangrene. Gangrene is where body tissues die as a result of severe infection or reduced blood supply.
The treatment for a foot infection depends on its severity. In most cases, a doctor will prescribe antibiotics to treat the bacterial infection.
If the infection has resulted in gangrene, the person may require surgery to remove the damaged toes or foot.
Lymphedema is a condition in which excess fluid accumulates in the body's tissues, causing swelling. Lymphedema occurs when a person's lymph nodes become damaged or are absent due to surgical removal.
The lymph nodes are glands that make up part of the body's immune system. They are responsible for helping to remove fluids from various parts of the body. If the lymph nodes in the pelvis are damaged or absent, this can cause fluid to build up in the legs.
A person who has lymphedema may experience a feeling of heaviness or swelling in their legs or other affected body parts.
According to Memorial Sloan Kettering Cancer Center, some treatment options for lymphedema include:
- bandaging the affected leg
- wearing compression stockings
- massaging the lymph nodes to encourage drainage
- performing gentle exercises to encourage drainage
- practicing good skincare to reduce the risk of infection and associated lymphedema
4. Venous insufficiency
The veins within a person's legs contain special valves that prevent blood from flowing backward. Venous insufficiency is a condition in which these valves no longer function properly. As a result, the veins no longer transport adequate amounts of blood from the legs back up to the heart.
When a person has venous insufficiency, their blood flows back down the legs and becomes trapped in the soft tissues of the lower legs and ankles.
A person with venous insufficiency may also experience:
- skin ulcers
- changes in skin color
According to Stanford Health, the treatment for venous insufficiency involves returning blood flow to the legs. This may involve:
- avoiding crossing the legs when sitting or lying down
- elevating the legs
- performing regular exercise
- wearing compression stockings
People may also receive medications to treat venous insufficiency. The type of medication a person gets will depend on the severity of their condition and their overall health.
5. Blood clot
A blood clot in the legs can cause a person's ankles and legs to swell. Blood clots in the legs tend to develop on one side of the limb.
There are two main types of blood clot:
- superficial blood clots, which occur in a vein closer to the surface of the skin
- deep vein blood clots or "deep vein thromboses" (DVTs), which occur in a vein deep within the body
A person should seek immediate medical attention if they experience any of the following symptoms of a blood clot:
- swelling and pain in one leg
- a heavy ache in the affected leg
- an area of warm skin on the affected leg
- an area of red skin behind and below the knee
- a change in the color of the leg
- low grade fever
Sometimes, a piece of the clot breaks loose and travels to the heart, lungs, or brain. This can be life-threatening if left untreated.
Typically, people who have a blood clot receive anticoagulant medications, which help prevent clots from getting bigger. They also help prevent new clots from forming.
Two common anticoagulant medications are heparin and warfarin.
6. Liver disease
The liver produces albumin, which is a protein that prevents fluid from leaking out of blood vessels and into surrounding body tissues.
A diseased liver does not produce enough albumin. Liver disease can, therefore, cause fluid to pool in the legs, ankles, and feet.
The only cure for liver cirrhosis is a liver transplant. However, treatment aims to manage the disease and prevent further complications. Treatments can also help to alleviate some of the symptoms of cirrhosis.
People who experience swollen legs as a result of cirrhosis may require diuretics, such as spironolactone or furosemide. People may also need to reduce their dietary intake of salt, as doing so can alleviate fluid retention.
7. Kidney disease
The kidney's main role is to regulate the amount of water in the body, and balance levels of salt and other minerals in the blood.
Kidneys that are severely damaged by disease are unable to filter the blood effectively and excrete fluid and other waste products through urine. This can lead to a buildup of fluid and other waste products within the body, including in the lower legs and ankles.
Some other early warning signs of kidney disease include:
- swollen hands or feet, or persistent puffiness around the eyes
- more frequent urination, especially at night
- high blood pressure, or hypertension
- blood or protein in the urine
The treatment for kidney disease depends on its underlying cause. According to the National Kidney Foundation, some causes, such as urinary tract infections and kidney stones, respond well to treatment.
Kidney disease may also occur as a result of an underlying medical condition, such as high blood pressure or diabetes. In such cases, a doctor will prescribe medications to manage these conditions and slow the rate of kidney disease.
8. Medication side effects
In some cases, medications can cause a person's ankles or legs to swell. Some medications that may cause swelling as a side effect include:
- hormones, such as estrogen
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- diabetes medications
- calcium channel blockers
If a person experiences side effects from their medications, they should talk to their doctor. The doctor may suggest lowering the dosage of the medication or switching to a different drug altogether.
People should not stop taking their medication without the approval of their doctor.
When a woman is pregnant, it is normal for some swelling to occur in the feet and ankles. The swelling may be worse if a woman is on her feet during the day.
However, sudden or severe swelling in the legs, ankles, or feet could be a sign of preeclampsia. Preeclampsia is a condition characterized by high blood pressure during pregnancy. It can threaten the safety of the woman as well as the unborn fetus.
Other potential signs and symptoms of preeclampsia include:
- swelling in the face and hands
- vision changes
- infrequent urination
- abdominal pain
- nausea and vomiting
Preeclampsia subsides after a woman has given birth. A woman should talk to a doctor about the symptoms she is experiencing so the doctor can help to determine the best way to handle the pregnancy.
A person should see their doctor or healthcare provider if they experience any of the following symptoms in the legs and ankles:
- sudden swelling
- unexplained swelling
- additional symptoms, including shortness of breath, fever, and pain
A doctor can help diagnose underlying conditions. In most cases, treating the underlying condition will help alleviate swelling in the legs and ankles.
In some cases, making certain lifestyle changes may help prevent or alleviate swollen legs and ankles. These lifestyle changes include:
- frequently checking the feet for bruises, cuts, and scrapes, especially if diabetic
- performing regular exercise
- eating a healthful diet that promotes heart, kidney, and liver health
- avoiding contact sports that can cause injury to the legs and ankles
Swollen legs and ankles may be a result of a benign cause or a potentially life-threatening condition.
A person should see their doctor if the swelling is sudden, unexplained, or accompanied by additional symptoms.
It is not always possible to prevent swollen legs and ankles. However, there are steps a person can take to reduce the risk of such issues. These include exercising regularly, following a healthful diet, and protecting the legs from injury, where possible.